This invention relates generally to steam turbines, and more particularly, to an exhaust hood used with a steam turbine.
At least some known power plants include a low pressure steam turbine (LP) coupled to an intermediate pressure (IP) and/or high pressure (HP) steam turbine to drive a generator. Within known LP turbines, expended steam is channeled into an exhaust hood from the LP turbine. The LP turbine exhaust hood facilitates separating steam under vacuum from atmospheric conditions, while providing support to rotating and stationary turbine components. As is known, the stationary components generally direct the steam towards the rotating components at a pre-determined angle to facilitate rotor rotation and thus, power generation.
At least one known LP turbine exhaust hood is fabricated from a plurality of complex plate metal shapes coupled together to form a shell assembly. The shell assembly is then machined to facilitate an interface between internal and external components used for steam turbine construction. The upper and lower halves of the exhaust hood are then coupled together along a horizontal joint to form the exhaust hood.
At least one known LP turbine exhaust hood is fabricated solely from steel material. Although such hoods may be more structurally sound than other known hoods, such exhaust hoods are heavy and may be awkward to assemble and move, because of the weight, the cost of manufacturing and transporting the exhaust hood is also increased in comparison to other known hoods.